SF6 GAS MONITORING High & Medium ­Voltage Gas density ­monitor Hybrid gas density monitor Gas density ­senso

Trafag — Swiss solutions for maximum accuracy The Swiss-based Trafag stands for precise, reliable and maintenance-free instruments developed for the monitoring of SF6 and other gases in the field of high- and medium-voltage switchgear. Trafag guarantees outstanding accuracy and operation in the widest temperature range on the market. Superior SF6 gas density monitoring for maximum safety Gas density is often indirectly determined by the gas pressure using manometers or pressure sensors. As the pressure in the hermetically closed volume varies enormously with temperature, such devices need temperature...

Trafag’s gas density monitoring devices Trafag’s product range of gas density measuring devices splits into three different product groups: The ­mechanically working Gas Density Monitor, the electronic Gas Density Sensor and the Hybrid Gas Density Monitor, monitoring both mechanically and electronically. Trafag Gas Density Monitor Unique SF6 monitoring with reference gas comparison ­ The Gas Density Monitor functions on the principle of reference gas comparison and therefore no temperature compensation is necessary. It works electromechanically and is thus independent of electrical energy supply....

Trafag Gas Density Monitor 87X6 Unique SF6 monitoring with reference gas comparison The mechanical, self-acting device is based on the superior reference gas principle which does not need temperature compensation. It therefore not only covers all standard applications but also maintains highest accuracy over a very wide temperature range. It allows use of different gas mixtures or the application in montane altitudes or arctic temperatures down to minus 60  It is equipped with high-performance micro °C. switches and does not need any electrical energy supply. This precise and maintenance-free...

For other available pressure connections: See data sheet www.trafag.com/H72502 Data sheet sensors controls

Trafag Gas Density Sensor 8774 Unique electronic SF6 gas density monitoring with quarz tuning fork The Trafag gas density sensor type 8774 was specifically designed for monitoring insulation gases. This unique patented sensor technology opens new paths for the energy distributing industry to realize comprehensive trend analysis and monitoring. It measures directly and continuously the gas density providing an analogue or digital output signal. The version with digital output signal also provides the signal of the gas temperature. Advantages Continuous digital or analogue output signal usable...

Technical data Gas Density Sensor 8774 Principle Oscillating quartz measurement Digital output signal Current pulses Material pressure connection Digital density signal Pulse frequency Material tube Digital temperature signal Pulse width Operating & Media temperature –40 ... +70 °C Analogue output signal Measuring range Analogue density signal Current loop Sensor supply analogue ouput Sensor supply digital output Sensor supply digital output O-Ring/joint torique/o-ring Various pressure connections available

Trafag Hybrid Gas Density Monitor 878X Unique SF6 monitoring: Combined mechanical AND electronic monitoring The Hybrid Gas Density Monitor combines the advantages of the proven mechanical monitor based on the superior reference chamber with the unique electronic gas density sensor. The combined technology has local switches / read-out and allows remote surveillance and trend analysis. The compact all-in-one-device with a single pressure port operates reliably and maintenance-free under harsh conditions indoors and outdoors. It is accurate over a wide range of temperatures and altitudes. Advantages...

... and the electronic gas density sensor The constant resonant frequency of a quartz oscillator under vacuum is compared with the resonant frequency of an identical quartz situated in the sample gas. The difference in the resonant frequency is Functional diagram: Analogue signal output Fr Oscillator Mixer SF6 Electrical connections and wiring diagram Δp (SF6) Finit element stress analysis of an oscillation tuning fork Up to three galvanically isolated micro switches actuate different alarm signals. proportional to the density of the sample gas. This difference is processed into an analogue output...

Trafag Hybrid Gas Density Monitor 878X For other available pressure connections: See data sheet www.trafag.com/H72502 ■Data sheet

Options and Accessories Rain cover with separate ­thermal ­insulation Foam cover with window Intank pressure connection Radial pressure connection

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